Street sheet pavement or roadway.



771,952. v PATENTED OCT. ll, 1904.

E. J. WARREN. STREET SHEET ,PAVEMENT 0R ROADWAY.

, APPLICATION FILED JUNE 21, 1902. No MODEL.

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UNITED STATES Patented October 11, 1904.

FREDERICK J. WARREN, OF NEWTON, MASSACHUSETTS.

STREET SHEET PAVEMENT OR ROADWAY.

SPECIFICATION forming part of Letters Patent No. 771,952, dated October 11, 1904.

Application filed June 2l, 1902. Serial No. 112,713. (No model.)

T0 au whom it may concern:

Be it known that I, FREDERICK J. WARREN, a citizen of the United States, and a resident of Newton, in the countyof Middlesex and State of Massachusetts, have invented a new and useful Improvement in Street Sheet Pavements or Roadways, of which the following is a full, clear, and exact description, reference being had to the accompanying drawing, forming a part of this specification, in explaining its nature.

My invention relates to a pavement, and particularly to the stony elements forming a portion thereof, which stony elements consist of porous stone saturated or filled in whole or in part with a bituminous composition applied thereto artificially in anydesired Way.

In the type of pavement known as bituminous macadam, of which I am the inventor, there is employed for forming the wearingsection of the pavement or roadway mineral (stony) ingredients of such sizes and of such proportions with relation to each other and of such quantity as to form a base having inherent stability to the wear of traiiic substantially independent of the bituminous composition which is employed to seal the voids of the base and form therewith a solid water and weather proof structure. As the principal wear of traiiic comes upon the mineral elements, it is desirable that they should be of a character to resist such wear, either because of their hardness or durability or disposition not to fracture or powder. In many parts of the country stone having these properties in whole or'in part and quite suitable for such use is obtainable. In other parts of the country the stone is not available, because it does not possess the requisite properties. I have ascertained, however, that stone of suiiicient porosity may be made available and useful where otherwise it would not answer the requirements of the pavement.. Such a stone is one having a suificient porosity to receive and hold a bituminous composition supplied it by soak-v ing or by pressure applied positively or by means of a vacuum or In any other desired l way. Such stone is so treated either in large pieces or in pieces of the size used for composing the mineral base of the pavement, accordmg to the character of the stone and its susceptibility to receiving the bituminous composition. The mineral ingredients (stony pieces) thus prepared for use in the pavement will consist of the stone and the bituminous composition with which they are wholly or in part impregnated and which imparts to the mineral ingredients properties which they did not before possess and by which they are rendered much less friable and more dense and better adapted to receive the wear of trafc and to conform to such wear without being wasted by being converted into dust or small pieces, which have no power to reunite or recombine with each other and which the addition of the bituminous composition gives them. A bituminous-macadam pavement made of bituminous stone or mineral ingredients of this character combined with suiiicientbituminous composition to unite them will possess many of the advantages of the bituminous-macadam pavement made of the stony elements having the natural advantages for this use to which I have referred and will make a wearing-section much superior to one composed of non-bituminizedsoft porous stone, which otherwise must be employed to make it commercially possible to lay bituminous macadam in sections of Vthe country having only this stone.

I will now describe'the invention in conj unction with the drawing, forming a part of vthis specification, wherein the figure represents in a conventional way in vertical crosssection a pavement having the features of my invention.

Referring to the drawing, A represents the subfoundation of a street pavement or road- Way;-B, the wearing-section of such a pavementor roadway applied to the subfoundation and consisting of mineral ingredients of the desired range as to size and proportions and which I prefer shall ybe in quantity sufcient to provide a structure having inherent stability to withstand the wear of traiiic and which stony elements are of a porous character and have been saturated or filled in whole or in part with a bituminous composition. These bituminized porous mineral ingredients are combined together and united to the subfoundation by a bituminous composition at least suii'icient in quantity as compared with the stony ingredients to completely fill the IOO interstices which would otherwise exist were they laid upon the foundation without such a medium, and I prefer, although this is not essential on account oi' the bituminous composition within the stony ingredients, that the bituminous composition be applied to the bituminized stony ingredients before they are laid upon the subt'oundation and to then lay them thereon to any desired depth-say from one to three inchesMand at any desired temperature and to there compact them into a solid water and weather prooil layer by means of pressure applied to the body of coated bituminized mineral ingredients and to any desired extent and duration.

Among other advantages of the invention are the following: It prevents the wasteful disintegration of the stony elements. It prevents the stony elements from absorbing the bituminous composition used to combine it together, and the bituminous composition or oil which is absorbed by the stony ingredients may be used to reinforce the bituminous composition used in the cement or mastic. It also preserves the stony elements from attacks by water and provides them with a durability which they would not otherwise possess.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States--- l. A pavement comprising mineral ingredients ot' a porous character, the pores of which have been lilled, or largely filled, arti- {icially by a bituminous oil or composition to form independent combined stony and bituminous elements oi' any desired sizes and of any required proportion of such sizes combined with a bituminous composition intimately mixed therewith for filling the voids between or uniting said ingredients.

2. A pavement or roadway consisting of natural porous ingredients or elements, the pores of which are artificially illed, in whole or in part, with a bituminous oil or composition, whereby the ingredients are made weatherprooil and their wearing properties increased, combined with a uniting bond of bituminous composition intimately mixed therewith.

3. A pavement comprising mineral ingredients of a porous character said ingredients being of varying sizes and the sizes proportioned to give the pavement an inherent stability, the pores of the ingredients filled with a bituminous oil or composition and a bituminous cement or binder for uniting the ingredients to each other in quantities to completely occupy the interstices existing between such ingredients. v

FREDERICK J. WARREN In presence of- RALPH LWVARRN, ALBERT C. WARREN. 

